In the telecommunication system, a transmitter usually includes an analog device, e.g. a power amplifier, with uneven characteristic frequency response in the transmitter circuit. This may result in a fact that the flatness of output spectrum of the transmitter cannot meet the requirements of wireless local area network (WLAN) standards, and even the distortions of memory effect. Such distortions make the transmitted signal, especially for a low power signal, affected by the nonlinear effect in the analog device.
Therefore, it is in need to develop a new method for equalizing the transmission spectrum of a wireless communication transmitter.